1. Field of the Invention
The present invention relates to an apparatus and a method for monitoring and/or controlling the transportation and/or the handling of multiple products, preferably for transporting and handling sheet-like products, in particular printed products such as newspapers or magazines, as claimed in the preamble to claims 1 and 15.
2. Discussion of Related Art
When printed products such as, for example, newspapers, magazines, catalogs, brochures and the like, or other sheet-like flexible products, are further processed, they are conveyed along from handling and/or processing systems by a transportation apparatus and thus finished by different handling and/or processing stations of the system. The transportation apparatus generally comprises endless transportation belts or chains, on which grippers or clamps are provided that in each case grip at least one product and convey it along through the system. The products are handled at the handling stations, for example by being folded, pleated, stapled, receiving an insert, being glued, cut, labeled, sorted, collected, packaged or wrapped, wherein products are transported, stored temporarily, separated or branched off between the individual stations at high speed. Capacities of 40,000 to 80,000 copies per hour can be achieved using such systems and transport apparatuses. Such a system is known, for example, from WO 2007/012206 A1.
The transportation apparatus and the individual handling stations are monitored and controlled with the aid of a computer, wherein the individual products or the grippers that grip a product can be marked so that a product or a gripper can be individualized. The marking can be read using suitable reader devices in real time so that it is known at any time where said product is located and the system can be controlled accordingly. Such a monitoring method is described, for example, in WO 2008/144945 A2.
A further method for identifying printed products is known from EP 0 810 967 B1, wherein an identity address is again associated with each gripper. Multiple grippers of a certain chain length of the transportation chain are here combined to form a section and a code is assigned to the section. It is intended that the chain length of a section here is so short with respect to the elasticity of the chain that variations in the chain length of each section compared to the spacing of the grippers can be ignored. It is thus possible to reduce measurement errors which can occur when specifying a gripper, owing to a change in length, for example caused by thermal expansion of the chain, wear on the chain or length tolerances. First the start of a section is determined by the code using a code sensor. Then the number of grippers is counted using a position sensor until the sought gripper has been identified. The sections and the grippers are thus determined in real time with the cycle time of the transportation chain.
In the known methods for producing printed products or other sheet-like flexible products, it is possible for a data bottleneck or overload to occur during the data transmission, owing to the high cycle time of the transportation apparatus and the multiple individual handling stations that need to be provided in each case with data on the identity of a product or a gripper according to the cycle time of the transportation apparatus. This can lead to inaccuracies in conveying and identifying products and hence to errors in product production or even to failure of the production system.